HEAT-PUMP-TYPE HEATING DEVICE

摘要

A heat pump type heating device includes: an indoor side heat exchanger (26); an outdoor side heat exchanger (27); low-pressure side compressor (31) and high-pressure side compressor (32) sequentially compressing refrigerant sent from the outdoor side heat exchanger (27); a first decompression device (36) decompressing the refrigerant sent from the indoor side heat exchanger (26); a gas-liquid separator (38) separating the refrigerant sent from the first decompression device (36), into a gas phase and a liquid phase; a second decompression device (37) connected to a liquid phase side of the gas-liquid separator (38) and decompressing the refrigerant sent from the gas-liquid separator (38); an injection pipe path (51) connected to a gas phase side of the gas-liquid separator (38) and guiding the refrigerant sent from the gas-liquid separator (38), to between the low-pressure side compressor (31) and the high-pressure side compressor (32); and a control unit (46) controlling a decompression ratio of the refrigerant in the second decompression device (37) such that the refrigerant flowing in the injection pipe path (51) is brought into a gas-liquid two-phase state. With such a configuration, there can be provided a heat pump type heating device having a simple configuration and having sufficiently improved heating ability.